Electric transformer.



Patented Dec. I9, I899. J. W. PACKARD.

ELECTRIC TRANSFORMER.

(Application filed Jan. 19, 1899.)

(No Model.)

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No. 639,276. Patented Dec. 19, I899. J. W. PACKARD.

- ELECTRIC TRANSFORMER.

A lication filed Jan. 19, 1899.)

(Application filed Jan. 19,

UNITED STATES PATENT OFFICE.

JAMES \V. PACKARD, OF XVARREN, OHIO.

ELECTRIC TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 639,276, dated December19, 1 899. Application filed January 19, 1899. $erial No. 702,693. Nomodel.)

To all whom it may concern:

Be it known that I, JAMES W. PACKARD, a citizen of the United States,residing at WVarren, in the county of Trumbull and State of Ohio, haveinvented certain new and useful Improvements in Electric Transformers,of which the following is a specification.

My invention relates to improvements in the cores of transformers and tovarious details of construction and arrangement, all of which will befully described hereinafter in connection with the accompanyingdrawings, in which Figure 1 is a rear View of the transformer, part ofthe casing being broken away to show the interior construction. Fig. 2is an end view of the transformer. Fig. 3 is a plan view of the samewith cover removed. Fig. 4 is a vertical section on the line at l ofFig. 3, the winding being shown in full. Fig. 5 is a perspective view ofone form of my improved core. Fig. 6 is a View of two of the strips orlaminze of which the core is composed. Fig. 7 is a perspective view ofone end of a coresection. Fig. 8 is a plan ,view of an assembling-box;Fig. 9 is a perspective view of another form of core embodying myinvention. Fig. 10 is a plan view of core-section shown in Fig. 9, withwinding added. Fig. 11 is a perspective view of the end of one of thecoresections illustrated in Fig. 9. Figs. 12 and 13 are perspectiveviews of the side and end sections of a core, respectively, showing amodification.

Referring to Figs. 1 to 4, inclusive, A indicates the casing of thetransformer, and a a top or cover of the casing. The casing is providedon its back with two pairs of hooks 1, into which fit cross-bars 2 of aframe, upon which the transformer may be hung when it is desired tosupport it upon a pole. To the ends of the bars 2 are attached verticalbars 3, which have rectangular hooks 4. at their upper ends adapted tofit over a cross-arm upon a pole.

At each end of the casing, near the top, is a depending hook, underwhich a rope may be passed for the purpose of hoisting the transformer.The hooks 5 are on projecting brackets 6, which are used as supports forthe bolts 7, by means of which the covers are fastened.

The bolts pass through holes in the covers and corresponding holes inthe brackets 6.

The transformer-core B is a rectangular structure composed of strips orlaminae, which are interlocked, as will be hereinafter ex plained. Thestrips forming the core are securely held together by metal clamps 8,which are insulated from the core by strips 9 of suitable material. Theclamps 8 of the core rest upon ,the bottom of the casing, and the coreis centered and held from lateral movement by projections 10, extendingupward from the bottom of the casing at its sides and ends. After thetransformer is set into the casing a pair of stout bars 11 are placedacross the top of the casing a short distance above thetransformer-core, the ends of the bars being held in recesses beneathshoulders 12, which are cast on the inner face of the casing. Tappedinto the middle of each of the bars 11 is a set-screw 13, the lower endof which is arranged to bear upon the clamps 8 at the top of the core.The clamping-screws 13 therefore hold both the bars 11 and thetransformer tightly in their respective positions in the casin g, thebars being pressed upward and the transformer downward.

The wall 14E of the casing extends upward part way to the cover. Outsideof the upper portion of this wall, at the corners of the easing, arecompartments 15, which have outer walls 16, fitting the cover. In thebottoms of these compartments 15 are the insulatingbushings 17, throughwhich the wires enter and leave the transformer. Fastened to the insidewall of the casing is a porcelain eonnection-board 18 for connecting theprimary coils in series or multiple.

Figs. 5, 6, and 7 illustrate the construction of a simple form of coreembodying my invention. The sides and ends of the core are formed ofstrips of thin iron, out as shown in Fig. 6. All of the strips are outsquare at one end and inclined at the other, the inclined end preferablymaking an angle of forty-five degrees with the longer side of the strip.The pieces for the sides are all exactly alike, and the pieces for theends are exactly alike also, but preferably shorter than the sidepieces.

In Figs. 12 and 13 a simple modification of the invention isillustrated. A side section of the core is shown in Fig. 3, composed ofrectangular strips 13 and strips it, which are inclined at both ends,the bundles of strips L3 being arranged alternately with the bundles ofstrips 44. All of the strips in this side section are of the same lengthand arranged to register at their back edges 45, thus forming solidends,'which are adapted to be held in a chuck. The end sectionillustrated in Fig. 13 is composed of bundles of strips t6, which a reinclined at both ends and adapt ed to fit against the inclined ends ofthe strips at. Between the bundles of strips it are alternate bundles ofshort rectangular strips -17, which fit against the ends of therectangular strips The manner of assembling the strips to form the sidesmay be explained with reference to Fig. '7. The strips are assembled inbundles, each containing a given number-- say two, three, or four. Thebundles are then assembled, with the inclined ends arranged alternatelywith the square ends. alternate bundles are arranged with their inclinedends at the top, and the adjacent bundles are arranged with their squareends at the top and their inclined ends at the bottom. All the stripsconstituting the side sections of the core are exactly of the samelength, and when assembled their extreme ends are made to register,forming a straight line 22 along the outeredge. The end of the sectionadjacent to the line 22 is solid and adapted to be clamped and held in achuck without injury.

The core-section construction above described has a number ofadvantages. The plates can all be formed by shearing, which is very muchcheaper than punching the plates with dies. It will be obvious that thelaminae may be formed by shearing sheetmetal plates into strips and thenshearing the strips on alternate square and diagonal lines. It is notessential that the angle of the inclined end should be forty-livedegrees. It may be more for the sides and less for the ends, or viceversa, the sum of the two angles being ninety degrees. It is mostconvenient and economical, however, to shear on an angle oi forty-livedegrees, as shown in Figs. 6 and 7.

Another advantage of my improved core is that the mortises onlyextendhalf way through the ends of the side sections, leaving the remainder orback portion of each end solid and'adapted to be grasped by a chuckwithout danger of bending the plates. On one side the core is solid tothe end of the section, as shown along line in Fig. 7. The core can bechucked for winding without putting filling-pieces in the mortises.

Another advantage of my core construction is found in the ease withwhich the strips for the side sections can be assembled. I assemble themin a box 1), comprising a base 23 and box-like projections 2st. The boxends Thus the 21- are of such size and are arranged so that the squareends of the plates fit in them exactly when the plates are laid on thebase 23. In assembling a core section the workman simply places thestrips in the box D, being careful to get the same number of strips ineach bundle and to arrange the successive bundles with the inclined endsalternately at opposite ends of the box. The strips may be compressedand fastened together by a wrapping of heavy paper in the usual mannerbefore they are removed from the assemblingbox.

My invention is applicable to-cores having other forms of cross-section.Thus in Figs. 9, 10, and 11 I have illustrated it as applied in theconstruction of a core the side sections of which have a star-shapedcross-section, as illustrated in Fig. 10. This star-shaped cross sectionis better adapted for winding than the rectangular cross-section of thecore illus trated in Figs. 5 and 7. By assembling the strips properlythe eight projecting corners of the star-shaped section can he broughtinto a circle, as illustrated in Fig. 10, which shows a coil in diagram.

Referring to Figs. 9, 10, and 11, it will be seen that the side sectionsof the core are constructed of a number of groups of wide plates 25, cutand arranged exactly as those shown in Fig. 7, and a series of groups ofnarrow plates 26, arranged on each side of the wide plates. The narrowplates are preferably of the same length the wide plates, and theirinclined ends are preferably cut away at a less angle than forty-fivedegrees, so that the plates in the end sections maybe all of the samewidth, as shown in Fig. 9. The middle plates of the end sections havetheir angular ends cut on an angle that is a complement of the angle ofthe side plates 25, and the outer plates of the end sections also havetheir angular ends cut on an angle that is the complement of the angleof the side plates 2 The end section of the core shown in Fig. 5 isformed by stacking the successive groups of strips with their inclinedends turned in opposite directions, the inclined end of each groupprojecting beyond the square ends of the adjacent groups. Instead ofstacking the plates for the ends before assembling the core the sidesections of the core maybe set up and the groups of end plates inserted,three or fou r at a time, in their proper positions be tween the sidesections, the square ends titting against the square ends of the sidesections and the inclined ends fitting in the recesses between thesquare ends of the side sections and abutting against the inclined endsof said side sections. The end sections of the form shown in Fig. 9 areconstructed in substantially the same manner.

Having described my invention, what I claim, and desire to secure byLetters Patent of the United States, is-= 1. In a converter-core, theside sections composed of groups of strips of equal length, the groupsbeing arranged side by side and having square and inclined endsalternating, and the extreme ends of all of the strips bein g arrangedto register, whereby the sections are provided with solid ends adaptedto be held in a chuck for winding, substantially as described.

2. In a converter-core, the side sections composed of groups of stripsof equal length which are square at one end and inclined at the other,the groups being arranged side by side with the square and inclined endsalternating, and the extreme ends of all of the strips being arranged toregister, whereby the sections are provided with solid ends adapted tobe held in a chuck for winding, substantially as described.

3. A converter-core having its sides and ends built up of groups ofstrips each having a square end and an inclined end, the said groupsbeing arranged with the inclined ends 1 alternately facing in oppositedirections, the i ends of all the strips in the side sections beingarranged to register, and the inclined ends of the strips in the endsections being arranged to break joints with the-adjacent square ends ofsaid end sections and to fit between the square ends of the sidesections, substantially as described.

4. In a converter, the combination with the casing and the core, of theprojections upon the bottom of the casing for holding the lower end ofthe core, shoulders at the upper end of the casing, transverse barsinserted under the shoulders and above the core, and setscrews extendingthrough said bars and bearing upon the upper end of the core,substantially as described.

5. In a converter, the combination with the casing and two pairs ofdependinghooks upon the back thereof, of the frame comprising horizontalbars for engaging said hooks and vertical bars attached to thehorizontal bars and provided with hooks at their ends, substantially asdescribed.

In testimony whereof I afiix my signature in presence of two witnesses.

JAMES XV. PACKARD.

Witnesses:

W. .D. PACKARD, M. S. ANDaEWs.

